You will probably receive lots of suggestions about your antenna. My
comments a

1. Longer is not better. Once an antenna becomes too long, it becomes more
directional (in odd ways) and may have more tendenacy to overload the
receiver. On the normal shortwave bands, receiver sensitivity is not the
issue (assuming a reasonably practical receiver); the signal-to-noise ratio
is the key element. A longer antenna can increase the signal but it usually
also increases the noise to the same degree and this does not accomplish
anything (except possibly overload the receiver).
2. A preselector can help prevent overload and may be a reasonable idea on a
less expensive receiver. (But it is not necessary; try working without it.)
3. A vertical or horizontal antenna (or a combination) can work. A
horizontal antenna may be less prone to "static" in your area.
4. Does the receiver have two antenna input terminals, with neither
"grounded" to the chassis? If so, a dipole might be appropriate. More
likely, it has a single terminal possibly with a second terminal optionally
"grounded". In this case, a single wire to the antenna might be better.
(The "feedline" to the antenna is part of the antenna also; try to keep it
away from electrically noisy things.)
5. With a single wire antenna, try the receiver with and without a "ground"
connection. It will probably be better with the "ground". You are unlikely
to need a ground stake. Try connecting to the "third pin" (ground) of your
electrical socket. Or, try two or three wires of different lengths (15 - 25
feet) laying on the ground (or under a carpet, etc). For receiving only,
you can try many different things --- there is no "right" answer.
6. For listening on typical shortwave bands, an outside antenna wire perhaps
35-40 feet long should be sufficient. For what you describe, the compass
orientation will not matter much. If possible, have the antenna up at least
30 feet and a little away from the house.
7. You did not ask about a feedline. For a single wire you could use coax.
What might be better is twin line with the antenna end of one side of the
feedline connected to nothing. The receiver end of this "nothing side"
would be connected to the ground terminal of the receiver.

All my suggestions will be shot down on various technical points, but they
may be reasonable for getting started.

Possibly the most important thing is to start understanding shortwave
propagation. What times are best to listen for Europe on which shortwave
bands? There are no definite rules here; the condition of the ionosphere
varies from day to day and hour to hour.

Bill
W2WO